The internet is an increasingly international network of computers that supports various forms and levels of communication. For instance, on the world wide web (WWW), information can be presented on universally available pages commonly known as websites. The internet also supports one-on-one communication between end-users via electronic email, instant messaging, and voice over IP (VoIP) communication.
Because of the open nature of the internet, security issues involving network communications have presented themselves. As an example, hackers have attempted, and often succeeded, in disrupting and disabling computer systems via the Internet. An example of such harm is a distributed denial of service (DDoS) attack, in which multiple compromised systems flood the bandwidth or resources of a targeted system, usually one or more web servers. In addition to malicious network attacks, errors in network routing data may result in undesirable network traffic. For example, popular sites having misconfigured DNS servers can direct traffic to unexpected targets or top-level domain (TLD) operators
In order to counteract malicious attacks on the network, packet filters have been used to increase network security and decrease undesirable traffic. Filters can be used to limit certain kinds of communications by denying the passage of packets through network interfaces. An example of packet filters are the filters used with the PortMaster network interface available from Portmasters.com of Houston, Tex. Filters for restricting network traffic are applied by the PortMaster network interface. As packets attempt to pass through the network interface, filters created by a system operator analyze the header information in the packet and either allow the packet to pass through the network interface or cause the packet to be discarded.
Despite the functionality provided by currently available systems for filtering traffic transmitted through a network, there is a need in the art for improved methods and systems to filter network traffic.